In recent years, LED elements, which are semiconductor elements having long lifetime and excellent drivability, have been widely used, for example, in illumination because they have, in addition, more miniaturized size, good light emitting efficiency and clear light emission color. In more recent years, there has been used LED light emitting devices of additive color mixing type which emit white light by enforcing concurrent light emission from LED elements for respective three colors; red (R), green (G) and blue (B).
For LED light emitting devices of additive color-mixing type, in order to realize light emission color with good color mixing property, the red, green and blue LED elements are known to be arranged on a substrate so that lines connecting these elements form an isosceles triangle (for example, JP 2011-233671).